The present invention relates generally to electronic solid state and integrated circuit devices. More specifically, the present invention relates to apparatuses for dissipating heat generated by such devices.
In the electronics and computer industries, it has been well known to employ various types of electronic device packages and integrated circuit chips, such as the PENTIUM central processing unit chip (CPU) manufactured by Intel Corporation and RAM (random access memory) chips. These integrated circuit chips have a pin grid array (PGA) package and are typically installed into a socket which is soldered to a computer circuit board. These integrated circuit devices, particularly the CPU microprocessor chips, generate a great deal of heat during operation which must be removed to prevent adverse effects on operation of the system into which the device is installed. For example, a PENTIUM microprocessor, containing millions of transistors, is highly susceptible to overheating which could destroy the microprocessor device itself or other components proximal to the microprocessor.
In addition to the PENTIUM microprocessor discussed above, there are many other types of semiconductor device packages which are commonly used in computer equipment, for example. Recently, various types of surface mount packages, such as BGA (ball grid array) and LGA (land grid array) type semiconductor packages have become increasingly popular as the semiconductor package of choice for computers.
In addition, microprocessors are commonly being installed onto a circuit board which is, in turn, installed into a motherboard or other similar primary circuit board. For example, microprocessors, such as the Pentium II and the Celeron from Intel, are "processor cards" which are installed into a motherboard of a computer in similar fashion to the way a modem is installed into a motherboard. On a given processor card is typically the processor semiconductor device package itself along with any other chips or semiconductor devices that are necessary for the operation of the card, such cache chips, or the like. The processor package may be installed into the processor card via a pin grid, ball grid, land grid array and with a socket such as a ZIF or ball grid socket.
In similar fashion to the earlier semiconductor devices discussed above, the processor cards like the Pentium II and Celeron also suffer from excessive generation of heat. In particular, the processor semiconductor device package on the card generates the heat which is of most concern. A given surface of the component will, as a result, be very hot. If such heat is not properly dissipated, the processor semiconductor device package and the entire processor card or component will eventually fail. Understanding the need for heat dissipation and the connection of heat sinks, the manufacturers of processor cards typically include holes completely or partially through the processor card to facilitate the installation of heat sink assemblies thereto. Commonly, an array of at least four holes are present to receive heat sink devices.
In view of the foregoing, efforts have been made to supply a heat dissipating member, such as a heat sink, into thermal communication with the processor card and more specifically, the processor semiconductor device package. These efforts commonly employ the available holes present in the processor card to serve as anchors for the receipt of a heat sink assembly. For example, prior art attempts include an extruded heat sink assembly with a base and an array of fin members emanating upwardly therefrom. The base includes a number of through holes which correspond with the arrangement of the holes provided by the manufacturer of the processor card. The heat sink assembly is secured to the processor card by screws which are hand-tightened to the desired tension and communication between the base of the heat sink and the processor card. These heat sinks attach directly to the heat generating package or the housing containing the package, such as in a Pentium II environment.
In addition, heat sink assemblies have also been available which provide a heat sink base and associated fins along with a spring clip which engages the holes in the processor card and spans across the heat sink base to secure it in place. While relative easy to install, this attempt in the prior art is not capable of fast tension adjustment of communication between the heat sink base and surface to be cooled and requires tools for installation.
In addition to the processor cards of the prior art, processor semiconductor device packages may also be installed directly into a main circuit board, such a motherboard, in similar fashion to the older Pentium or 486 processor packages. Some manufacturers are also providing through holes in the motherboard itself to permit the attachment of heat sink assemblies as an alternative to attaching the heat sink assembly to the semiconductor package itself or the socket into which it is installed. In similar fashion to the processor cards discusses above, these processor package arrangement suffer from similar problems associated with the attachment of heat sink assemblies to avoid overheating problems.
In view of the foregoing, there is a demand for a heat sink assembly that attach to a heat generating semiconductor device package without attaching to the semiconductor package itself. In addition, there is a demand for a heat sink assembly that can quickly and easily attach to holes provided proximal to the device to be cooled without the need for tools for installation.